SSOK UNINTENTIONAL FLOATERRalph Wallio, WØRPK WØRPK
at netINS.net

On
January 8, 2000 Pete Sias, WBØDRL, released yet another Sky Science over Kansas
(SSOK) high altitude balloon mission from Salina, Kansas. The results were very
unusual and totally unexpected. The balloon envelope did not ascend and then
immediately burst as all previous experience predicted. Instead, the balloon
envelope achieved a lengthy floating phase before finally bursting some
700-miles to the east. For 2.5-hours the balloon and payload used 170-knot
winds at 116,000-feet to make a very nearly straight track that finally ended
near Fort Wayne, Indiana.

A few of us have been considering all the available evidence and asking
questions of professional experts with the goal of understanding what caused
this unusual flight profile and how it might be duplicated. These are important
questions because, if a similar flight profile with a latex balloon envelope
can be routinely created, the cost of floating a payload at 100+kft for a few
hours would come down by a factor of roughly 10:1 from costs for zero-pressure
polyethylene envelopes. Investigation, discussion, planning and preparation
continue toward an attempt to recreate this floating phase. (Update Sep05:
there have now been four unintentional floaters. We do not yet understand what
is happening.)

There are several interesting stories from this mission, not the least of which
is how several Amateur Radio Operators supported this mission in several ways.
One of the many efforts has been the collection and integration of downlink
telemetry. The 700+ mile track made it impossible for any one station to
capture all transmitted data so it has been very important for many observers to
submit files to this process. Pete thanks all of the following for submitting
their data:

Mark Conner, N9XTN, produced APRS+SA maps as he has for
predictions and actual tracks of numerous high altitude missions. Mark is a
professional meteorologist contributing his expertise to this ongoing
investigation and to high altitude ballooning in general. For readers not
familiar with APRS mapping, the track line is actually a continuous plot of
over 1900 GPS-fix positions reported at 10-second intervals. It is interesting
to note the almost straight ground track from Topeka, Kansas to almost Fort
Wayne, Indiana. Placing a straightedge on the track line finds only very minor
meandering.

Ralph Wallio, WØRPK, produced flight profile charts in EXCEL using GPS
telemetry values, TIME, LATITUDE, LONGITUDE and ALTITUDE, and derived values,
VERTICAL VELOCITY, TRACK VELOCITY and TRACK BEARING. In these charts, note the
rapid decline in normal ascent vertical velocity to zero just before MET
3.0-hours and the constant altitude of 116,000-feet and track velocity near
170-knots from MET 3.0-hours (Kansas
City) to burst just before MET
5.5-hours (Fort Wayne).